为探索不同基质和生根促进剂对荔枝圈枝压条生根效果的影响,以桂味荔枝品种为试材,对圈枝压条技术进行了试验.结果表明,基质采用岩棉,并拌以浓度为50mg/L的ABT1号溶液,可有效提高圈枝苗的生根率、生根数量和根系长度.

火力楠属于一种速生、用途广泛、适应性强、经济价值高的常绿阔叶树种.其枝叶繁茂、树干通直,具有生态、观赏及经济价值.通过对火力楠苗木育苗进行施肥培育研究,提出火力楠苗木育苗施肥养分元素配比;通过分析氮碳钾对火力楠苗木生长的影响,验证了施肥处理对火力楠苗木生长的影响程度,提出适宜育苗的方式和施肥方案.

为了解台湾桤木(Alnus formosana)在广西的适应性,研究其在广西不同纬度(鹿寨县、来宾市、南宁市、玉林市和凭祥市)的苗期生长情况、光合能力及固氮能力.结果表明,台湾桤木苗木在各引种地生长表现和光合特性差异显著.2019年8月,苗木地径为13.36～16.76 mm,苗高为96.4～135.8 cm,干重为177.3～237.2 g,根瘤鲜重为2.71～3.40 g,根瘤酶活性为157.1～238.4μmol·g-1·h-1,单株固氮能力为180.7～243.5μmol/h.净光合速率为12.9～16.1μmol·m-2·s-1,气孔导度为0.266～0.386 mol·m-2·s-1,胞间CO2浓度为282.5～327.7μmol/mol,蒸腾速率为3.17～3.33 mmol·m-2·s-1,最大光合速率为12.7～17.8μmol·m-2·s-1,光饱和点为1805.0～1896.4μmol·m-2·s-1,光补偿点为37.2～51.7μmol·m-2·s-1.纬度与根瘤酶活性、气孔导度、光饱和点和光补偿点呈显著或极显著负相关.台湾桤木在玉林市、南宁市和来宾市苗期具有更强的生长能力.

探索适宜的施肥方法和施肥量对大花序桉容器苗育苗基质和苗木生长的影响,以期为大花序桉容器苗施肥提供指导.通过对大花序桉容器苗每隔15 d施加不同浓度的复合肥为施肥处理,对育苗基质土壤和苗木生长进行分析,并通过隶属函数值综合评价不同施肥方式对大花序桉容器苗育苗基质和生长综合效益影响.结果表明:施肥处理降低了基质土壤pH值,对土壤有机质、全氮磷钾、速效氮磷钾等影响不显著,施肥处理能显著提高苗木的高度、地上部分生物量以及鲜质量,对地径和总生物量有一定的提高但效果不明显.综合评价得出:通过第一次施0.3％复合肥8 mL,15 d后第二次施0.4％复合肥8 mL,30 d后施0.4％复合肥8 mL,对大花序桉容器苗的土壤和苗木生长发育综合效益影响最好,可作为大花序桉育苗初期用肥参考.

Based on the investigation of the growth characters in a 4.5-year-old open-pollinated Michelia macclurei progeny testing stand,the comparison and variation analysis were applied to determine the family quality and to estimate genetic parameters and genetic gains.The results showed that the height,DBH and volume growth of the progeny test plantation were significantly higher than that of the control,and there were relatively high variations among tested families which possessed breeding potential.According to the comparison of significance of difference,two families were selected.Their average genetic gain was 76.65%,28.03%,13.25%,respectively.These two first-class families could be used for establishing the improved generation seed orchard of Michelia macclurei and for popularizing and appling as excellent breeding materials.

<正>竹柏(Podocarpus nagi)为古老的裸子植物。树叶形奇异,终年苍翠,树干通直圆满,树态优美,叶茂荫浓,抗病虫害强,为理想的庭园风景树种,近年来被广泛用于庭园、住宅小区、街道等地段的绿化。1竹柏生物学特性竹柏别名桫杉、山杉、那木、竹叶柏、鸡屎堆树等,为罗汉松科竹柏属常绿乔木。高达20～30m,胸径0.5～0.7m;树干通直,树皮褐色,平滑,薄片状脱落;小枝树生,灰褐色;叶子为变态的枝条,交叉对生,质地厚,革

Eucalyptus cloeziana is a potential saw timber species,the study on provenances and families shows that mean HT and mean DBH arrives to 7.45 m and 7.10 cm at 2.5 years old,and there are significant differences between provenances and families for all growth traits.The heritability of HT,DBH and Volume of family are 71.1 %,75.1 % and 68.5%,and also the heritability of HT、DBH and Volume appearing to be the older the bigger.There are also much higher genetic gains for DBH and Volume of the families that arrive to 12.68% and 25.26%,and for HT just is 6.68%.Therefore,DBH and Volume of families will be the main factors in the early selection.8 seedlots and 20 families are selected as recommended potential improved materials by the way of index selection,